Many types of transaction cards (account cards, identification cards and the like) have been used by individuals to gain access to account files in a bank or similar institution, to gain access to secure areas, or to initiate some similar transaction enabling them to access otherwise restricted information stored in the institution. Not infrequently, the person using the card is not the person to whom the card was issued (i.e., not an authorized user of the card), but a person who has found, stolen, or manufactured (perhaps duplicated) the card with the intent to use it to defraud a bank or similar institution out of thousands, or perhaps even millions of dollars.
Heretofore, relevant information such as account number or code, employee number, social security number and the like, have been readily recorded or otherwise included on the card (i.e., embossed, magnetically or optically encoded on the card). A card of this type, and a system which utilizes such a card, are shown, for example, in U.S. Pat. No. 3,862,716, entitled "Automatic Cash Dispenser and System and Method Therefor," issued Jan. 28, 1975 to Robert Black and Christopher Hall.
Because of the dire consequences (i.e., loss of thousands, even millions of dollars by banking and other institutions) that could be occasioned if the security of such a card-utilizing system is breached by an unauthorized card user, a more secure card and system which would make the probability of said breach more remote would not only be useful, but very desirable. What is needed, therefore, is a card (and a system for utilizing the card) which actively contributes to the security process, i.e., a card that aids the system in securing data entered into the system, rather than merely passively reproducing prerecorded data when read.